Gaseous-discharge device



Nov. 7, 1950 P. w. sTUTsMAN GAsEous DISCHARGE manon Filed June 24, 1947Patented Nov. 7, 1350 "GAsEoU's-DISCHARGE DEVICE Paul W. Stutsman,Needham, Mass., assignor to Raytheon Manufacturing Company, Newton,Mass., a corporation of Delaware Application June 24, 1947, Serial N0.756,683

6 Claims. (Cl. Z50-27.5)

This invention relates to gaseous-discharge devices, and moreparticularly to a cold-cathode gas tube with a collector electrode. Y

An object of this invention is to devise a socalled sub-miniature typebulb with a flat pinch press having a plurality of vitreous insulatingsleeves sealed thereinto in order to provide shielding means for aplurality of leads extending into said bulb. I p 'I 1 Another object isto provide a gas-discharge tube having-anelectrode positioned in thepath of the discharge between ,the anode and cathode, from whichelectrode a voltage may be obtained for utilization in a separatecircuit, the voltage of said electrode being controllable by saiddischarge. v

A further object is to provide a cold-cathode gas tube with a collectorelectrode. v

A still further object is to devise a collectorelectrode type gas tubewhich will be fired in response to a certain'predetermined voltagedifference between its anode and cathode, but will not be iired by acomparable voltage difference between the collector electrode and thecathode.

An additional objectl is to provide a collectorelectrode gas Ytube whichwill not be iired when either its anode or its cathode is at zero orground potential, but will be fired when the anode potential and thecathode potential diiIer from' zero in opposite directions by equalpredetermined amounts.

The foregoing and other objects of the invention will `be bestunderstood from the following description of an exemplification thereof,reference being had to the accompanying drawing, wherein: I v

- Fig. 1' is a central vertical cross-section, on an enlarged scale, ofa gas-discharge tube according to this invention;

Fig. 2 is a horizontal cross-section taken along line 2--2l of Fig. 1;

Fig. 3 is a horizontal cross-sectiontaken along line 3-3 of Fig. 1; y e

Fig. 4 is a partial horizontal cross-section taken along line 4-4 ofFig. l; and

` Fig. 5 is. a diagram illustrating a circuit in which my tube may beutilized. Y

Now referring to the drawing, and particularly to Figs. 1-4 thereof, a.vitreous envelope I of the fiat-bulb type has a flat external pinchpress 2 at its lower endand a tipped-0E exhaust tubulation 3 at itsupper end. Said envelope is designed to house or contain the electrodestructure of the tube of this invention, and is evacuated and suppliedwith gas through tubulation 3 and thereafter sealed in accordance withthe usual practice. Leads 4, 5, 6, and 'I are sealed throughv press 2and are utilized to convey energy t0 the various electrodes and toassist `in supporting'such electrodes in position inthe envelope. Lead 4Vis the starting anode lead, lead 5 is the main anode lead; lead E inthe collector A electrode lead, and leads] is the cathode` lead, Inorder to properly shield the leads 4, 5, and Ifrom each other and fromthe space through which the discharge is intended to take place insidethe envelope, three upstanding vitreous insulating sleeves 8, 9, and Illare provided, each of these sleeves being fused into press 2 at thelower end of such sleeve. Sleeve 8 is concentricl with but spaced fromlead 4, sleeve 9 is concentric with but spaced from lead 5, while sleeveIII is concentric with but spaced from lead 1. Leads 4, 5, 6, and Tallextend in straight lines, vertically and substantially parallel to eachother, as shown. v

Inside bulb or envelope I, near the upper end thereof, there is provideda flattened tubular hollow metallic cathode member or electrode II whichis open at its lower end but isv closed at its upper end by a metallicdisk member I2 which is welded at its edges to the ycathode I I. CathodeII is of such a size that it substantially lls the interior of envelopeI. The upper end of cathode II is held in the center of bulb I by meansof a mica spacer I3 which resiliently engages, at portions of theperipherythereof, the inner wall of said bulb and which is fastened tocathode II by any suitable means, for example by a tab I4 integral withthe cathode, which tab extends upwardly through an aperture `in spacerAI3 Vand is bent over to firmly engage the top surface offsaid spacer.In order to more firmly support cathode I I in position, a metallicbracket member I5 is wrapped firmly around sleeve |0 near the upper endthereof, and is also welded to the inner wall of cathode II. Sleeve IIJis terminated immediately above the upper end of bracket I5, and theupper end of lead 'I extends slightly above the upper end of saidsleeve. In order to electrically connect-cathode lead 'I to cathode II,a horizontally-extending lead wire I6 is provided, said lead wire .beingwelded to lead 'I at one end and to the inner wall of cathode II at itsopposite end. Hollow iron ywire members II are suitably secured to theinner wall of cathode I-I, near the upper end thereof, these memberscontaining therein an electronemissive material (not shown). Meansv forreadily releasing said material is provided by regustructure I9.

Inside bulb I, a substantial distance below cathode II, there isprovided a substantially horizontally-extending starting anode electrodeAs shown in Figs. 2 and 3,- this structure consists of a substantiallyU-shaped horizontal metallic frame 20 having xed. thereto a metallicwire screen 2I which covers approximately two-thirds of the area of theU, from the base thereof toward the free ends of the legs of the Us VInorder to support starting anode.l9 in position, the free l'endsof thelegs of the Uv are attached', as by welding, to the respective oppositeends of a double-ended transversely-extending metallic bracket member22, the central por-` tion of which is wrapped tightly Yaround sleeveI'.v In order to assist in supporting` starting anode I9, and also toprovide el'ectricalconnection thereto, theupperend of startinganode lead4 is welded to theV centralportion'of 'the base bf the U-frame 29. Y.Avnode electrode 23 is a metallic wire which is secured, as by a.butt-weld, to the upperendcf anode lead 5 and which'extends verticallytoa point a. substantial distance below starting electrode ,I9 butsomewhat above the upper end of sleeve 9. Y VV Surrounding the upperexposed end of anode 23 isa collector electrode structure generallydesignated by 24. Structure 24 consists of a hollow metallic tube 25open at its lower end and having a metallic wire screen 26 extendingentirely over its, upper end, said screen being attached to said tube.Tube 25 .is coaxial with anode 23 and sleeve 9, the lower end of saidtube tightly engaging the outer surface of sleeve 9 in an area at theupperend of said sleeve. Tube 25 extends upwardly above the upper end ofanode 23, so that screen 26` is above the upper end of said anode, butis spaced therefrom by only a rather small distance, on the order of0.06 inch, for example, while the distance from the upper end of anode23 to the upper end of sleeve 9 is also rather small, `on the order of0.04 inch, for example. Therefore, collector electrode'24 is spaced veryclosey to anode 23, both radially and also longitudinally (by screen26). ScreenZB, and therefore also collector electrode 24, are positionedin the path of the discharge which can occur between anode 23 andcathode II K In orderv to assist in maintaining collector electrode 24in position, as well as to provide electrical connection thereto, ametallic bracket member 21, which has arcuate portions at its ends, hasVthe top edge of' one end thereof welded to the lower edge of tube 25;the arcuate end portionsofgsaid bracket member are wrapped tightlyaround the two sleeves 9 and ID. The

upperend of collector electrode lead' is Welded tothe central portion ofbracket member 21 to provide electrical connection to collectorelectrode 24.

It should be made clear, at this point, that in Fig. 2 the collectorelectrode structure 24 has not been shown for reasons of clarity, as itis felt that the showing of such structure in the middle of screen 2l inthis figure would be confusing. In Fig. 3, the screen 26 has beenomitted for the `same reason.

The upper end of sleeve 8 lies in substantially the same horizontalplane as the upper Vend of tube 25. As is shown in Figs; 3 and 4, thelongitudinalV axes of leads 4,v 5,:.a'nd 'Land of sleeves 3, 9, and I0,all lie onthefmaorv axis of bulb I, with that of lead 5 and sleeve 9near the interi section of the major and minor axes of said bulb.

As. may be seen in Figs. 1,3, and 4, both screens 25 and 2I arepositioned in the anode-cathode l In gas-discharge' tubespthe total tubevoltage Y drop. is made up of the cathode drop, the positive columndrop, and the anode drop. In the tube of this -finvention, the collectorelectrode 24 is spaced from anode 23 a distance approximately`'corresponding to that representing. theA anode drop or anode fall ofpotential inthe cathodeanode discharge. s

Nowreferring to, Fig. 5, which.V illustrates a circuit invwhich thetube. of this invention could bev used, cathode lII is connected througha resistor 28, having a value on the order of 100,000 ohms', to themovable contact 29 of asingle-pole double-throw switch, one xed contact30 of which is connected to groundfor a Zero potential point and theother3xed contact. SI' of which is connected to the negative terminal ofa source 32 of direct voltage, the positive terminal lof said sourcebeing grounded as shown; source 32 may have an electromotive. force ofvolts, for

example. Y

Starting anode I9 is connected, through a current-limitingresistor v33,to anode 23 and to the movable contact 34 of arsingle-pole doublethrowswitch. One xed contact 35 of this lastnamed switch is connected toground, while theother fixed contact 36 is connected to the positiveterminal of a source 31 of direct voltage, the negative terminal of saidsource being grounded as shown; source 3l may also have an electromotiveforce' of 100 volts, for example.

Collector electrode 24 is connected through a high resistance'38, on theorder of 10 megohms for example, to ground. The collector electrodeVvoltage may be abstracted from the tube by leads 39 and 4D and appliedthereby to any suitable voltage utilization circuit, suchas in a comput-`ing machine, for example; lead 39 is connected on contact 30 andcontact 34 is on contact 35.V

Under these conditions, both kanodes and the cathode are grounded or atyzero potential, so the discharge in the tube is not started.

" If,fn'ow, either contact 29 .is moved to'contactl 3l or' contact 34 ismoved to contact 36,Y but not both-either the cathode or the anode willstill be at zero potential, 'there will be a potential.

difference of only 100 volts` between starting anode f'l9 and cathodeII, and` the` discharge inY the tube will still not be started.

.If both contacts 29 and 34 are moved to theV right (Contact 29 tocontact 3| and contact 34 to contact '36), either simultaneously orsuccessively, a voltage of plus 1GO volts is applied to anode 23andstarting anode I9, and a voltage of minus 100 volts to cathode H.There will then exist the required 200 volts potential differencebetweenstarting anode I9 and cathode II; a glow discharge will beinitiated between said starting anode and said cathode, causing the mainglow discharge between anode 23 and cathode I I to begin, thus firingthe tube, since anode 23 has sufcient positive voltage with re-v spectto cathode VII to sustain the discharge. Resistor 33 limits the ilow ofcurrent through the starting anode branch circuit when the gaseousdischarge is initiated. From the above, it may be seen vthat the tube ofthis invention is red when and only when its anode voltage and itscathode voltage differ from zero, in'opposite directions, by equalpredetermined amounts. This firing, discharge of the tube, or conductionof the tube, is caused to occur independently of the voltage oncollector electrode 24, as will be brought out subsequently.

When the cathode-anode discharge begins, the potential of collectorelectrode 24 rises, substantially instantaneously, to one which isrelatively close to that of the anode 23. This rise of potential, inresponse to conduction in the tube, appears between leads 39 and 40 'andmay be utilized in a suitable voltage utilization circuit. It is notnecessary to understand exactly why this change of potential occurs, butpresumably this rise or increase of positive potential of the collectorelectrode results from the collection of positive ions by suchelectrode. The electrode 24 is positioned in the path of the main glowdischarge.

It has been found that, for any given gas or mixture of gases inenvelope I, the Vparticular collector electrode structure disclosed,consisting of both the solid-walled metal tube 25 and the wire screen26, gives the closest possible approach to a minimum potentialdifference between anode 23 and collector 24 during the discharge.

The provision of screen 26 over the end of tube 25, rather than entirelyclosing the end of said tube, allows the discharge to pass between anode23 and cathode II through said screen.

It has been found that different gases have different anode falls ofpotential (which falls are approximately equal to the potentialdiierence between anode 23 and collector 24 during the discharge, asnoted above), and that the various anode falls of potential are of thesame order of magnitude as the rst ionization potential of thecorresponding gas. With the kryptonxenon mixture described above, it hasbeen found that there will be a potential diierence of approximatelyvolts between anode 23 and collector 24 during the discharge, while withthe neon-argon mixture there will be a potential diierence ofapproximately 20 volts, and with helium a potential difference ofapproximately 24 volts. Thus, with a neon-argon mixture and with avoltage of 100 volts on anode 23, as above described, the potential ofthe collector 24 will be approximately plus volts during the discharge.'and'thisrise of potential of said collector from zero to 'approximately80 volts willr occur substantially simultaneously with the initiation ofthe cathode-anode discharge.

It has been found that the resistor 38 in series with the collectorelectrode must have a high value of resistance; if this resistance ismade to'o low, the power necessary to hold the collector electrode at ahigh potential will be beyond the capacity of the tube.

By the inclusion in starting anode I9 of wire mesh or screen, and alsoby the placing of said starting anode between collector electrode 24 andcathode I I, I have in effect provided a shield between the collectorelectrode and the cathode. As a result, no discharge will be initiatedeven if the collector 24 has a potential comparable to that at which thestarting anode would cause the tube to rire, as long as the anode has apotential less than its required starting potential. In other words, thecollector is not capable of starting the discharge at a voltage equal tothat at which the starting anode would cause a discharge to occur. Thetube will not conduct, Vin the vexample given, if Vthere is a potentialof zero or plus volts on the collector, if the voltage on either theanode or the cathode is zero, but thev tube will conduct, independent ofthe voltage on the collector, if there is plus 100 volts on the anodeand minus 100 volts on the cathode. Thus, premature or improper firingof the tube is prevented.

'At' this point, it is desired to be brought out that the tube of thisinvention is extremely small in size. For example, in a tube constructedaccording to this invention, the major external diameter of the bulb wasapproximately 0.36 inch, the minor external diameter was approximately0.3125 inch, while the overall length of the bulb (from the bottom ofpress 2 to the top of tubulation 3) was approximately 11/2 inches.

Sleeves B, 9, and I0, which are vitreous or madeV of insulatingmaterial, are for the purpose of shielding the lead wires which theyrespectively surround, so as to prevent discharges occurring betweenportions of the electrodes where such discharges are not desired, or inregions of the space where discharges are n'ot desired or where, if theyoccurred, they would interfere with proper functioning or operation ofthe device.

Of course, it is to be understood that this invention is not limited tothe particular details as described above, as many equivalents willsuggest themselves to those skilled in the art. It is accordinglydesired that the appended claims be given a broad interpretationcommensurate with the scope of this invention within the art.

What is claimed is:

1. A gaseous discharge device comprising an envelope containing anionizable gas, a metallic cathode and anode inside said envelope spacedfrom said cathode to provide a path therebetween in which a glowdischarge may be established, means for establishing a glow dischargebetween said cathode and said anode, and a collector electrodepositioned in said path at a distance from said anode substantiallyequal to that corresponding to the anode fall of potential of said glowdischarge.

2. A gaseous discharge device, comprising an envelope containing anionizable gas, a metallic cathode, a main anode inside said envelopespaced from said cathode to provide a path therebetween in which a glowdischarge may be established, a

amazes; `Y

electrode being caused to assume;apositivepotential-with'frespect to*said cathode by theestab-f,

lishrnentof'saide` glow discharge; andastarting anode positionedadjacent said cathode: between said electrode and: said cathodexto,establish said glow'discharge, said starting anode having aperforatedaportion extending j across the :discharge path between saidcathodeand electrode and intercepting all straight line discharge pathsYtherebetween to shield said cathode from said electrode,;thereby toprevent establishment of said glowdischarge by said electrode.

l 3. A gaseous discharge device, comprising an envelope containing anionizable gas, a metallic cathode and. anode inside said envelope spacedfrom said cathode to provide a path therebetween in which a gl'owdischarge may be established, a collectorelectrode positioned in saidpath at adistance from said anodeV substantially equal to thatcorresponding to the anode fall of potential ofsai'd discharge, and aperforated shielding elec-I trode intercepting all'straightline pathsbetween saidcathode and' said electrode for shielding said cathode fromsaid electrode, thereby to prevent establishment of saidrglow dischargeby said elec- 4. A gaseous discharge device, comprising an envelopecontaining an ionizable gas, a metallic cathode, a wire main anodeinside said envelope spaced from said cathode to provide a paththerebetween in which a glow discharge maybe established, a collectorelectrode positioned in said path at a distance ,from saidan'odesubstantially edual to that corresponding tothe anode fallof potentialofsaid'discharge; anda starting anode positioned adjacent saidcathode'to establish said glow discharge.

'52 A gaseous discharge device, comprising "an envelope containing anionizable gas, a metallic cathode, a main anode inside said envelopespaced from said cathode to provide a path therebetweenV inwhich a glowdischarge may be established, a collector electrode` positioned in saidpath at a distance' from said anode substantially equal to thatcorresponding to theA anode fall ofpotental of said'dischargaandastarting anode positionedl adjacent said;cathode betweenzsaidelectrodeand said cathode toest'ablish saidglow discharge, saidstarting" anode having a perforated portionxextending. across theAdischarge -path between; saidzV cathode and' electrode andV interceptingall straight lineA discharge paths therebetween'to shield said cathodefrom Said electrode, thereby` to prevent establishmentlof said glowdischargeby said electrode. f

6. A.. gaseous discharge device, comprising a.:

glass envelopey containing an ionizable gas,V a,

metallic cathode, a wire'anode inside said en.-v

velope spaced from said cathode to'provide a path therebetweenY in which"a glow discharge maybe;

established, va collector-electrode positionediinf said path at adistance from said anode sube'.

stantially 'equal to that corresponding to the anode fall-of:potentialof saiddischarge, and a perforated shielding lelectrode*"fintcrceptingf alli straight line paths between said cathodeandLsaid"electrode for shielding said cathode .iromlsaid7 electrode,thereby toprevent establishment ofisaid' giov/discharge by said electrode, vsaidcathoda;

anode, collector electrode, and shielding electrode having lead-in wiressealed through one end of:

" *nare-names CITED v The fourmngM le of this patent:

v UNITED STATES PATENTSv Number Narnle Date 1,939,063 Knowles Dec. l2,1933 2,053,501 Spencer Sept. 8, 1936 2,106,847 Knipekarnp Feb.v l, 19382,435,246 Stutsman Feb. 3, 1948 V'PAUL w. sTUTsMAN.

references are of record in the'V

